Hay fever is quite common in Japan, and as Spring comes, everyone starts using masks for protection. Normally, Japanese people use masks when they have a cold, or to avoid having one. It may seem kind of weird, seen from western countries, because almost no one uses it.
So, when we talk about Spring, we have to talk about Sakura! Japanese love watching them bloom, and there is actually an additional information to the weather forecast that shows a map of Japan, and where they are starting to bloom! :D
Moreover! Before that, there is even another map showing where the pollen is reaching to! Something like "pollen is starting to spread all over Kyoto, it is recommended to use your mask".
And yeah, there are A LOT on sale!